Filter



FIG. 1 is a front perspective view of a filter showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view, the right side view being a mirror image thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The material in dotted lines forms no part of our invention. 

The ornamental design for a filter, as shown and described. 